title: Prolonged QTc interval predicts all-cause mortality in patients with rheumatoid arthritis: an association driven by high inflammatory burden.
abstract: OBJECTIVE
  RA associates with an increased rate of sudden cardiac death (SCD). A prolonged QTc interval has been associated with arrhythmogenic and SCD in patients with long QT syndrome. Despite the previously reported contemporary association of CRP with SCD, thus far no studies have examined the association of QTc with mortality in RA, a condition characterized by high inflammatory burden. The aim of this study was to examine the role of electrocardiography (QT corrected interval) in predicting all-cause mortality in patients with RA who have an increased rate of SCD and a high inflammatory burden.
  
  
  METHODS
  Three hundred and fifty-seven RA patients with detailed baseline clinical characterization and 12-lead ECGs were followed up for a mean of 73.0 (S.D. 18.3) months. Linear and Cox regression analyses were used to identify variables that associate with QTc and examine its association with all-cause mortality.
  
  
  RESULTS
  The patients' mean age was 60.6 (S.D. 12.0) years, 267 (74.8%) were females and 54 (15.1%) died during the follow-up period. Age (β = 0.231, P < 0.001), gender (β = 0.137, P = 0.008) and CRP (β = 0.144, P = 0.006) associated independently with QTc in RA patients. The crude hazard ratio (HR) for total mortality per 50-ms increase in QTc was 2.17 (95% CI 1.21, 3.90). This association remained significant [HR = 2.18 (95% CI 1.09, 4.35)] after adjustment for identified confounders (cardiovascular and RA specific), but was lost [HR = 1.73 (95% CI 0.83, 3.62)] when CRP was included in the model.
  
  
  CONCLUSIONS
  A 50-ms increase in QTc interval associates with a doubling of the hazard for all-cause mortality in patients with RA. The observed contemporary association of QTc with CRP levels indicates a potentially hazardous interplay between inflammation and arrhythmogenesis. Future studies are needed to confirm the above findings and explore underlying mechanisms.
authors.affiliation: Hammersmith Hospital, Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK. v.panoulas@imperial.ac.uk.
authors.forename: Vasileios F
authors.initials: VF
authors.lastname: Panoulas
authors.forename: Tracey E
authors.initials: TE
authors.lastname: Toms
authors.forename: Karen M J
authors.initials: KM
authors.lastname: Douglas
authors.forename: Aamer
authors.initials: A
authors.lastname: Sandoo
authors.forename: George S
authors.initials: GS
authors.lastname: Metsios
authors.forename: Antonios
authors.initials: A
authors.lastname: Stavropoulos-Kalinoglou
authors.forename: George D
authors.initials: GD
authors.lastname: Kitas
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications / Q000401:mortality*; D002423:Cause of Death / Q000639:trends; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000150:complications* / Q000401:mortality; D008133:Long QT Syndrome / Q000150:complications* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D006113:United Kingdom / Q000453:epidemiology
keywords: QTc; death; mortality; prolongation; rheumatoid arthritis; sudden cardiac